Apparatus for acquiring and processing of physiological auditory signals

ABSTRACT

A diagnostic system for collecting, processing, recording and analyzing sounds associated with the physiologic activities of various human organs. The system includes a plurality of transducers placed on the body surface at the operator&#39;s discretion. The transducers are coupled to analog/digital signal processing circuitry for enhancement of the desired signal and exclusion of ambient noise. An A/D converter digitizes the incoming data and transmits data, which is divided into a multitude of discrete blocks, received over very finite intervals of time, to a computer workstation and moved through an analysis program sequentially. The program is displayed as a series of icons which depict operations that the program performs and which allow the operator to reprogram the system at any time. The data is finally displayed in graphical format and stored in memory as the program processes each block sequentially.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/785,357 filed on Mar. 23, 2006, the contents of which areincorporated herein by reference.

FIELD OF INVENTION

The present invention relates generally to the field of diagnosticmethods and systems, and particularly to the acquisition and analysis ofphysiological auditory signals.

BACKGROUND OF THE INVENTION

Throughout this application, various publications are referenced. Thedisclosures of these publications in their entireties are herebyincorporated by reference into this application in order to more fullydescribe the state of the art as known to those skilled therein as ofthe date of the invention described and claimed herein.

Auscultation of the lung and heart is probably the most widely usedphysical diagnostic method in respiratory and cardiac disease. However,due to the limitations of the human auditory system, auscultation hassuch low sensitivity and specificity that many physicians no longer relysolely on it as a diagnostic tool. Although digital acquisition andanalysis of physiologic sounds has the potential to be of tremendousdiagnostic/therapeutic benefit to patients, the medical community hasbeen slow to embrace this technology. In order to overcome thisobstacle, any system for digital acquisition and analysis of physiologicsounds must be lightweight and easy for individuals without technicalexpertise to operate and modify. In addition, all generated results mustbe presented in a format that allows for rapid interpretation andcorrelation with important physiologic values obtained from other tests.A description of the prior art and their perceived shortcoming relevantto the objectives of the present invention follows herein.

Physiologic sounds may be captured electronically, processed, andtransmitted back to the clinician thus enabling the human auditorysystem to obtain greater information conveyed by the signal. Forexample, U.S. Pat. No. 5,774,563 discloses a device for acquiringphysiologic sounds. Electronic circuitry embedded in the device enablesthe operator to filter and amplify the incoming signal. Furthermore,this device also allows the user to listen to the post-processed signalthrough implementation of earpieces. However, no plan is described forenabling clinicians of ordinary ability to modify the system. Thus, theeffective frequency range measured by this device is 70-480 Hz, which isessentially unalterable, has minimal clinical applications. In addition,this system does not provide a means for digitalacquisition/display/analysis of the recorded signal, which serves toseverely limit the use of this device in a clinical setting. Other formsof analogous art, which are based on these same principles, sharesimilar disadvantages.

Analogous inventions in the art have depicted devices capable ofacquiring, processing and digitally recording/analyzing physiologicsignals. U.S. Pat. No. 6,139,505 discloses an electronic stethoscope forthe digital acquisition and analysis of physiologic sounds. The deviceconsists of a microphone, which can be embedded inside conventionalchest pieces. After amplification and filtering, the signal istransferred to an analogue to digital converter (A/D converter) forcomputer analysis. The system disclosed contains a modifiable number ofindependent transducers to record physiologic sounds at any particularlocation, which the operator desires. The device allows foramplification/filtering of the recorded signal, store these recordingsin memory, perform root mean square (RMS) and time expanded waveformanalysis, and display data on a monitor for visual analysis/printing.This device is also fairly easy to modify/upgrade/repair and includes abuilt in program for analyzing respiratory sounds and generating aprobable diagnosis based on this information.

However, this device does not disclose a method to enable the physiciansto listen to the sound as it is being recorded, but instead, requiresthem to discern phases of the respiratory cycle simply by inspection ofthe time expanded waveform. The patent describes a method by whichphysiologic sound may be processed and transmitted to a computerworkstation using analogue circuitry which is bulky and not easilycustomized thus limiting the device's practical application. Further, noinformation is given about how this device can be used for higher levelanalysis (such as performance of Fourier Transformation or wavelet) ofthe desired signal, only time expanded waveform analysis and RMS of thecomplete spectrum are illustrated. These quantities give incompleteinformation regarding the sound and the program is not easilyoperated/modified by a clinician of ordinary skill. Lastly, no method isoutlined by the inventors for reducing the corruption of the data frominadvertent pickup of ambient noise or superimposed signals emitted fromother organs in close proximity to the transducer. The probablediagnosis product available with this device is also extremely limitedsince it provides no quantitative information regarding the degree offunctionality of the desired organ system. Although Murphy's electronicstethoscope represents significant improvement from analogous art as asystem for the display and analysis of physiologic sounds, thelimitations of this device as described above decrease its usefulness ina clinical setting.

Additional devices have been patented which attempt to provide moresophisticated means for mathematically analyzing physiologic sounds andtransmitting results to remote locations. One such example can be foundin U.S. Pat. No. 6,699,204, which illustrates a device for recordingphysiologic sound using multiple sensors that are secured to a patientvia a harness. Physiologic sound can be recorded by the sensors andrelayed to a processing station for filtering/amplification usinganalogue circuits. The signal is then transferred to a sampler Ech(sound card) for digital recording via analogue circuitry or modem (notshown). With the aid of a specialized calculation manager (Matlab® forexample), the device can evaluate a set of transformed intensity levels,each associated with a predetermined sound frequency and means forstoring each transformed intensity level in correspondence with anassociated frequency for the purpose of displaying these intensitylevels, transformed on the basis of frequencies as a spectralrepresentation of the auscultation sound.

The device depicted by Kehyayan et al. is a further improvement overanalogous art since it provides an accurate spectral representation ofthe auscultation sound as the intensity varies with time. However, aphysician of ordinary ability cannot be expected to have the technicalexpertise necessary to easily operate and/or modify this analysisprogram in order to examine a wide array of physiologic sounds. Also, noplan is outlined by the inventor for preventing extraneous sounds (fromambient noise or sound emitted from other organs) from influencing theresults displayed on the spectral plots. Lastly, the spectral plotscontain too much information for a clinician to interpret in a timelymanner. Thus, it is unlikely that the invention proposed by Kehyayanwill be useful in a practical setting, and thereby widely embraced bythe medical community.

SUMMARY OF THE INVENTION

It has been proven that organs in the human body emit characteristicphysiologic signals when they are functioning in the absence ofpathology. It is an object of the present invention to provide animproved system for accurately assessing organ (particularly lung)function and thereby facilitating the diagnosis of certain diseasesbased upon digital recording, processing and analysis of thesephysiologic sounds.

One of the main obstacles to widespread acceptance of electronicstethoscopes is that these devices are too cumbersome, and also, toocomplicated for health care professionals to operate in a professionalsetting. Thus, it is a further object of this invention to provide acompact, customizable device. But most important, the device will be animprovement over analogous art by providing a simple interface whichallows medical professionals with limited technical background to easilymanipulate vital parameters such as block length, overlap, samplingrate, low/high pass filtering, adjusting the Fast Fourier Transformation(FFT) and RMS analysis to cover any component of the frequency spectrum,and applying data windows without the need for computer programmingknowledge.

Another object of this invention is to boost the accuracy of recordingphysiological sounds by providing the physician with an efficient methodof eliminating background noise (which is either present in the ambientenvironment and/or emitted by other body organs in the vicinity of thetransducer) from the desired signal in real time. Accomplishing thistask will not only lead to greater accuracy in the measurement ofphysiologic sounds, but it will also allow the device to operate with agreater degree of autonomy when compared to analogous art.

Lastly, acoustic signals from human organs occur over many differentfrequency ranges (depending on the specific organ and any pathologypresent) and are often of minimal intensity. Therefore, detectingdifferences in these signals between normal physiologic and pathologicstates over a finite time interval for any given organ requires a systemof mathematical analysis with greater sensitivity than that described inmany versions of analogous art. Thus it is an additional objective ofthis device to provide a means for adjusting the frequency band in thePower Spectrum Density (PSD), which the RMS values are calculated from.The PSD results from performing the FFT on the digital datacorresponding to the audio signal.

As noted above, this invention relates to a system for recording andanalyzing physiologic sounds to provide the clinician with informationrelating to functional status of the organ being examined. Thisinformation may provide clues, that when combined with other elements ofa diagnostic workup (history, physical exam, lab tests, medical imaging,etc.) may facilitate the diagnosis of various disease states (pulmonarydisease for example). Consistent with other forms of analogous art, thesystem includes a plurality of transducers, such as microphones embeddedin small rubber tubes coupled to a thin plastic diaphragm(s) which maybe placed at pre-selected sites on the patient using either lightpressure or a harness of some type. Physiologic signals of interestvibrate the plastic diaphragm, which transmits the sound by moving airmolecules in the tube. The transducers detect these sounds and convertthem into electrical signals. The system contains a preamplifier thatnot only increases the intensity of the incoming electrical signal, butalso polarizes the transducers with an electromotive force (preferably48 Volts) applied equally to both inputs to the sensor with respect toground (phantom power). In order to provide this polarizing potentialhigh voltage commercial alternating current is converted to high voltagedirect current. This voltage is applied to same wires that carry theaudio signal. Since the preamplifier can supply such high voltage(unlike many computer sound cards available commercially) this inventioncan make use of transducers with higher signal to noise ratios thanthose used in analogous art. Furthermore, portability may be maximizedby supplying the phantom power through a rechargable battery.

The system also includes a digital signal processor for conditioning thesignal (filtering, gating, limiting, or excluding background noise). Inthe preferred embodiment of the invention, analogue circuitry or adigital signal processor employing Super Harvard Architecture (SHARC)can be added for additional filtering, expansion, compression orconversion of the processed signal back to sound energy thereby enablingthe operator to hear the altered sound in real time. After processing,the analogue signals generated by the transducers are converted intodigital data and transferred to a computer workstation. In order toincrease the portability of this device, digital data may be transmittedto the workstation over wireless internet. A further advantage ofutilizing a SHARC processor is that optimal settings for detecting soundfrom a variety of sources may be stored in memory for instantaneousrecall by the operator. These aforementioned settings which areprogrammed into the SHARC processor may enable the claimed invention toacquire properties of sound transmission which are identical to aconventional acoustic stethoscope. This is important because acousticstethoscopes remain popular in clinical settings due to the fact that atremendous amount of research has already been done with them and thesteadfast hesitancy among health-care professionals to abandon their useof these devices.

The computer station includes a microprocessor, input/output circuitry,and random access memory for data storage, one or more input devices(such as a keyboard or mouse), a modular interface with many differentgraphical displays of incoming data, and one or more output devices(such as a printer, monitor or modem for transmission over theInternet).

Executing on the computer is an application program constructed from aset of modular elements synthesized using a graphical programminglanguage. The application program collects the data and organizes itinto discrete sections (blocks) before moving it through though a seriesof modules. By clicking on any specific module with the mouse, theoperator can set the sampling rate, block size and overlap. Furthermore,the operator may elect to further high/low pass filter the datadigitally or apply a mathematical window analogous to FFT processing inorder to minimize distortion of calculated results.

After breaking the signal into multiple blocks (which correspond todiscrete time intervals) and then pre-processing these blocks, theprogram calculates the power spectrum density of the portion of thesignal contained in each block using the FFT. After calculation thecomputer displays the results graphically as a plot of Intensity vs.Frequency. These results are updated continuously as the PSD iscalculated anew for each incoming block and the results of the previousblock are saved in memory.

As the PSD is calculated for each incoming block, the computer mayexclude portions of the PSD that are outside the selected thresholdsspecified by the operator. This is possible because the program maycontain a trigger, which enables the operator to exclude portions of thespectrum, which are not of interest with a simple mouse click. Once thePSD is determined, the program calculates the root mean square (RMS)value of the signal in the frequency band(s) chosen by the operator. Thecomputer performs this calculation on each incoming block and displaysthe data as a list during the time of operation. This method is highlyadvantageous to the clinician since it takes a very complicated quantity(the PSD of each block that gives information about the power of allfrequency components in the block) and converts it into a simplequantity (RMS), while still relaying the necessary information about thesignal to the clinician. Secondly, by performing these calculations oneach incoming block of the data, the properties of the signal outlinedabove can be analyzed as they vary over time. The clinician can then usethis information about an organ's spectral characteristics to assess itsdegree of functionality in a quick, inexpensive, accurate andnon-invasive manner. The analysis program illustrated in the presentinvention can be used either as a stand alone application or incombination with a number of additional program elements which mayinclude patient's electronic medical records. As a result, this systemhas the potential to dramatically improve efficiency in the healthcaresystem and clinical outcomes for patients.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of the present invention may be further illustrated byreferencing the following description and corresponding drawings, inwhich:

FIG. 1 provides a general overview of the preferred embodiment of thepresent invention.

FIG. 2 is an illustration of the computer station component of FIG. 1.

FIG. 3A illustrates a block diagram of the preferred embodiment of thesignal conditioning station.

FIG. 3B illustrates a block diagram of the digital signal processordescribed in the preferred embodiment.

FIG. 3C illustrates a block diagram of elements utilized in dataconversion and transfer incorporated within the preferred embodiment.

FIGS. 4A-L illustrates a variety of operations which may be performed onthe acquired data by the digital signal processor.

FIG. 5 illustrates a display of the RMS values for the incoming signal(ambient noise) received from the test microphone. These values can behelpful in quantifying the effect of ambient noise on the calculation ofthe RMS values of the desired signal.

FIG. 6 is a flow chart of the data collection and analysis program. Eachicon represents an operation which is performed on incoming data andselecting a corresponding icon can modify these operations.

FIGS. 7A and 7B represent time expanded waveforms of physiologic sounds.

FIG. 8 is a graphical representation of the power spectrum densitycalculated using the Fast Fourier transformation from an incoming datastream representative of physiologic sounds received by the transducerpositioned over the heart.

FIG. 9 depicts the sequential display of RMS values calculated from thePSD after processing for heart sounds. This data may then be used toassess the degree of functionality of the target organ.

FIG. 10 depicts the PSD calculated from tracheal breath sounds using theFFT.

FIGS. 11A and 11B depict the sequential display of RMS values calculatedfrom the PSD after processing of the tracheal breath sound.

FIGS. 12A-12C depict the sequential display of values corresponding tothe maximum frequency 12A and corresponding intensity 12B/12C from thedesired portions of the PSD after processing of the incoming signal fromthe heart. Data is displayed as it is obtained from each incoming block.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 provides an overview of the sound recording and analysis systemof the present invention. This system includes a transducer 1, such asan analogue condenser microphone, which can be placed at various sitesaround the patient to listen to sounds emitted by different organs. Itshould be understood that the system could be expanded to includeadditional transducers 1 if desired so that data from multiple sites canbe collected concurrently. To isolate the sensors from external sounds(and thereby improve signal to noise), they may be embedded in thetubing/chest pieces of conventional stethoscopes. The transducer(s) 1may be held against the surface of the patient with mechanical pressureapplied by the operator, adhesive tape or suitable strapping to preventmovement during the data acquisition process.

Leads 2 extending from the sensors are balanced cables with XLR inputs97 that connect to a signal conditioning station. A suitable signalconditioning circuit for use in the present invention could be theEurorack 1202, a sound mixer 3 made by Behringer. This station performsmany important functions. First, it supplies the electromotive forceneeded to polarize the transducer 1. In the preferred embodiment, themixer 3 converts standard alternating current (120 volts) into directcurrent (48 volts). It has been proven that to accurately recordphysiologic sounds, it is important to have a transducer 1 with a highsignal to noise ratio and a flat frequency response. These types ofsensors may demand high voltages, which are not readily supplied byanalogous art that utilizes sound cards built into most commerciallyavailable personal computers 9 or batteries.

The voltage is then supplied to the sensor through both XLR inputs 97equally with respect to ground (phantom power) 93. The audio signal istransmitted through these same inputs approximately 180 degrees out ofphase of each other thereby ensuring a balanced signal. Balanced signalsare less corrupted by ambient noise relative to unbalanced ones. Insidethe stethoscope tube, sound energy generated from organs inside the bodyis converted into an electrical signal by the microphone. Thiselectrical signal (which is a representation of the sound) is thentransmitted to the mixer 3 though the same leads 2 that supply thevoltage in the manner described previously. To further prevent thisdesired signal from being corrupted by external electric/magneticfields, the cables may be shielded. The mixer 3 may have additionalports to receive electrical signal from additional sensors. In addition,phantom power 93 may be supplied via alkaline (such as the ART PhantomPower Adapter), or other rechargeable 9 volt batteries.

Once the electrical signal is received by the mixer 3, it may beamplified 255 and/or filtered 256. In the preferred embodiment the mixercontains circuitry 383, which can act as a high pass filter (80 Hz) 256and/or low pass filter (12 kHz) 256, although other frequencies arepossible. It should be noted that the invention gives the operator theability to bypass this processing if they choose. Afteramplification/filtering, the signal may be sent to a headset 4 where itis converted back to sound energy, thereby enabling the operator tolisten to the sound as it is recorded. The signal may also be sent forrecording on cassette tapes or it can be sent to a digital signalprocessor (DSP) 5. One such example is the DEQ 2496, a digital equalizerwith Super Harvard Architecture (SHARC) signal processors76,77,78,79,80,81,82,83,84,85,86,87,88,89,90 and specialized software,made by Behringer which is depicted in FIGS. 3A and 3B.

The digital processor 5 performs the fast Fourier transformation on thesignal and displays both the discrete frequency bands and the power ofthe signal in each band (power spectrum density) 621, as shown in FIGS.8 and 10, for example. One of ordinary skill in the art will understandthat the waveforms shown in FIGS. 8 and 10 (as well as other waveforms,such as FIG. 12A) are merely exemplary, and that the ordinate or Y-axisdemonstrates relative values, such as decibel (dB) shown, as well asother measures of PSD, such as, but not limited to, RMS. From here, theoperator can selectively amplify/attenuate components of the signal inany frequency band from 20-20000 Hz (similar to an equalizer) 612-615.Unwanted signal can be excluded by compressing 615 (the processorreduces the intensity of all signal components with a volume that isgreater than desired) or expanding 615 (reducing the intensity of allfrequency components with an intensity less than that desired by theoperator) frequencies detected by the transducer 1. Of note, the devicecan function as a noise gate and/or limiter if compression/expansion isperformed to a maximum degree. All operations undertaken by the digitalsignal processor 5 to alter the incoming audio signal can be displayedvia LCD, and device operations 612-620 and 622-623 may be saved inmemory by device operation 620 for instant recall by the operator atsome future time. The adjustment of stereo width function 623 may or maynot be necessary. It is understood that specific operations 612-619 ofthe digital signal processor 5 may cause the invention to acquireproperties of sound transmission similar to conventional acousticstethoscopes. This characteristic of the claimed invention is a valuableattribute, since a tremendous body of research has already beenconducted in the analysis of physiologic auditory signals using saidacoustic stethoscopes. Secondly, it is well known that such conventionalstethoscopes are still widely popular in the market place. Specifically,settings contained in the digital signal processor 5 may allowclinicians to measure blood pressure values, grade cardiac murmurs(I-VI) and listen to other physiological sounds in a manner whichcorrelates well with findings obtained from a conventional acousticstethoscope. The ability to perform compression/expansion is animprovement over other forms of analogous art since it allows the deviceto record physiologic sounds from the human body without having toconstantly be directed to by the operator. However, it should be notedthat the device might set up so that it is required to be directed bythe operator before making recordings.

Furthermore, the digital signal processor 5 contains a test transducer1, which can be deployed by the operator if desired. This testtransducer 1 may be affixed to body surface or exposed to the ambientenvironment. The test transducer 1 records sounds from sources thatmight corrupt the signal being recorded from the organ of interest. Thismay include noise present in the ambient environment or sound emittedfrom other organs in the vicinity of the target organ. The powerspectrum density 621 of these ambient signals can be used to calculateand display 622A the corresponding RMS values for the signal asdemonstrated in FIG. 5. The components of the undesired signal, whichinterfere with the signal of interest, are effectively quantified inreal time. The DSP 5 may transmit data directly to a computerworkstation 9 for further analysis via cable or wireless internetconnection 16, 17. This is a significant improvement over analogous artbecause it can be used to remove ambient noise that contains identicalfrequency components to those of the target organ, thus producing a muchclearer signal from the target organ in addition to enabling theclinician to obtain standardized measurements regardless of the noiselevel present in the ambient environment at the time of measurement. Theprocessing methods may include (but is not limited to) graphic 612,parametric 613, digital 614 and/or dynamic equalizers 615, as well assignal compression/expansion/boosting/cutting and feedback destruction622 or bypassed altogether 616.

After this additional processing, the signal from each analogue outputis transmitted to an analog-to-digital converter (A/D converter) 6,which may or may not be part of the computer station 9. The A/Dconverter 6 converts the processed audio information into a digital datastream for transmission to the workstation 9. One advantage of employinga SHARC processor 5 is that digital data may be transmitted to thecomputer workstation 9 over wireless internet 16,17. This process can beachieved by coupling the SHARC processor 5 to a modem 16 with a WiFi PCcard (not shown). Digital data acquired during stethoscope operation maybe transferred to a WiFi Access Point/Router 17, and afterward, sent toa modem 16 via CATS cable or WiFi USB adapter.

The sampling rate used in digitizing the data may be adjusted by theoperator and should be greater than 44.1 KHz with a bit rate preferablygreater than 24 bits per sample. The A/D converter 6 is preferablymulti-channel which may contain an additional preamp such as the EdirolUA-25 sold by the Roland Corporation. FIG. 3 is a schematic of all ofthe hardware components which comprise the preferred embodiment of theinvention (components for transmission of data over a wireless networkare not shown). FIG. 3A illustrates a first portion of a first schematicconnected to a second portion of the first schematic, illustrated inFIG. 3A(cont.), through lines (a)-(f). FIG. 3C illustrates a firstportion of a third schematic connected to a second portion of the thirdschematic, illustrated in FIG. 3C(cont.), through lines (g)-(v). Asuitable workstation 9 may be a personal computer of the E-machinesseries as sold by Lenovo, comprising a microprocessor 12, input/outputcircuitry 10, and memory for data storage 13, one or more input devices(such as a keyboard 8 or mouse 7), a modular interface with manydifferent graphical displays of incoming data as depicted in FIG. 6, andone or more output devices such as a printer 15, monitor 14 or modem 16for transmission over the Internet. As shown in FIG. 1, input/outputcircuitry 10, microprocessor 12, and memory for data storage 13 areinterconnected via bus 11. However, it should be understood that othermodels may be substituted. These computers are controlled andcoordinated by operating system 16A, such as Microsoft Windows XP orother system. The operating system 16A may also comprise a windowmanager 17A, printer manager 18 and additional device managers 21 inaddition to one or more device drivers 19,20,22 in order to allow thecomputer workstation 9 to interface with hardware components.

In the present invention digital data from the A/D converter 6 istransmitted to input/output (I/O) circuitry 10 of the computer via USBcable JK1. FIG. 2 illustrates the interaction of software elements onthe computer workstation 9 with the application programs 210,220,230 andoperating system 16A relationships shown by arrows 306,307,308 viasystem calls. The program (FIG. 6) is organized by a series of graphicalicons that are provided via specialized data acquisition software suchas DASY LAB 9.0, a product manufactured and sold by Capital Equipment.Each icon, constructed using a graphical programming language,represents a command(s) for the workstation 9 to perform. This program210 is fully customizable since simply inserting/deleting icons in theflow diagram can make new programs. All commands given to the analysisprogram by the clinician are accomplished via simple keyboard 8 entriesor mouse 7 “clicks”. Thus, knowledge of computer programming languages(which many health care personnel do not possess) is not a requiredprerequisite for proper operation of the instant device.

Prior to first listening to the sound the clinician chooses the samplingrate by clicking on a tab marked “experimental setup.” The A/D inputicon 404 receives data via I/O circuitry 10. The Recorder Icon 407displays the time-expanded function of the incoming signal illustratedin FIGS. 7A and 7B in accordance with the description set forth in U.S.Pat. No. 3,990,435. The clinician then clicks the Filter icons 405,406in order to select frequencies where the signal can be high/low passfiltered digitally. Some examples include digital high/low passfiltering, application of a windowing function to incoming dataanalogous to PSD calculation, adjustment of sample rate, block size,degree of overlap and recording time. Through the use of these icons,the clinician may also determine the characteristic (Butterworth,Bessel, etc.) and order of the digital filter. The clinician will clickthe Data Window Icon 408, to select the desired block length,appropriate mathematical window to fit the data with, and determine thedegree of overlap (if any) between successive blocks. The FFT icon 409in the program 210 instructs the computer to calculate the FFT on theportion of the signal represented by each block. The Y/T Icon 413enables the clinician to view a display of the PSD on a monitor 14 foreach block after it is calculated as illustrated in Figures FIGS. 8 and10. By clicking the FFT max icon 410, the clinician can specify thefrequency range within the PSD where both the frequency of maximumintensity and its magnitude may be calculated as illustrated in FiguresFIGS. 12A, 12B and 12C. These quantities may be displayed by the iconmarked “Digital Meter” 411 or List icon 412. By clicking the TriggerIcon, the clinician can determine which frequency components of the PSDwill be excluded from the RMS calculation (not shown).

Since different body organs emit sound in different frequency ranges,the ability to adjust the frequency range is vital if one hopes toconstruct a single device that can be used to analyze sounds from all ofthe different organs (not just lung). The Statistics Icon 414 instructsthe computer to calculate the RMS value of the signal in the desiredfrequency range set by the digital high/low pass filters 405,406 orTrigger Icon in the specified range. The List Icon 415 displays the RMSvalue sequentially as it is calculated from each incoming block as shownin FIGS. 10 and 12. Additional modules may be added to the program 210for the purpose of determining the magnitude of the change in RMS valueswith respect to time at a given anatomic position. These RMS values,either as displayed by the List Icon 415 or when combined withadditional analysis programs 220,230 on the workstation 9, give theattending physician a mechanism for comparing the intensity ofphysiologic sound recorded by the sensor in any desired frequency rangeand over any duration of time.

In operation, the sensors 1 are affixed to any part of the body surfaceaccording to the discretion of the clinician. The system is theninitialized and data is transmitted to application program 210, as thepatient inhales/exhales, sound is converted to audio signals which maybe amplified/filtered/processed before being relayed to both theclinician and the application program 210 in the computer workstation 9.At any instant in time (if the physician hears an interesting sound) thephysician can start the digital recording by clicking the Recorder Icon407, a green arrow in the upper left hand corner of the screen. Afterthe signal of interest is no longer audible, the physician may stoprecording by clicking the red square icon or specifying the duration ofrecording via the “Stop” icon 416. The computer recording may beinfluenced by the DSP 5 via compression/limiting 615 or equalization612,613,614 as described above. After recording is complete, theclinician may click the list icon 415 to obtain a columnar display ofthe desired RMS values. Review of this list may give the clinicianvaluable information regarding the degree of functionality/pathologypresent in certain organs (lung, heart, bowel, etc.). The settingsand/or outputs of the PSD (calculated from the Y/T icon 413), TimeExpanded Waveform 407, FFT Maximum 410, Filters 405,406 and List 412,415can all be saved in memory 13, printed on paper via printer 15 ortransmitted via modem 16 to another computer 9 though the internet. Itshould be understood that additional icons may be added to the programin FIG. 6 if additional data manipulation is desired. In addition,program settings for analysis of auditory signals from two or moredifferent sources (organs, ambient noise, etc.) such as the heart andtrachea (FIGS. 9 and 11) may be combined, thereby enabling the operatorto analyze discrete frequency bands within a signal. For instance, if anobserved physiologic sound is composed of sounds from the trachea andheart superimposed on each other, the operator may combine modules fromFIGS. 9 and 11 into a single program that will separately analyze thesignals from each source simultaneously. If there exists overlap,additional methods may be deployed to separate out the overlappingfrequency components of the two or more sources.

Lastly, data generated from this analysis program 210 may be integratedwith numerical/text data contained in a patient's electronic medicalrecords 220. The integration of data among these programs 210,220,230can be directed by an operator using a mouse 7, keyboard 8 or otherinput. U.S. Pat. Nos. 6,944,821 and 6,154,756 demonstrate two suchmethods for performing said integration of data contained on multipleprogram elements. Additional software programs 230 may combine data fromthe analysis program 210 and electronic medical records 220 for thepurposes of assessing target organ functionality, characterization ofpathology if present, and generating accurate predictions regarding thedegree of functionality of the target organ system in the near future.

A description on the preferred embodiment of the invention outlines avery specific method for analysis of physiologic sounds. The device asclaimed is capable of variants and it should be appreciated by oneskilled in the art that substitution of materials and modification ofdetails can be made without departing from the spirit of the invention.

What is claimed:
 1. An apparatus for acquiring and processingphysiological sounds comprising: a sensor comprising a diaphragm,wherein said sensor is configured to be positioned on a body surface,and said sensor is configured to convert analogue signals, in responseto vibration of said diaphragm by said physiological sounds, into anelectrical output representative of said physiological sounds; ananalogue to digital converter operatively coupled to said sensor,wherein said analogue to digital converter is configured to convert saidelectrical output into a stream of digital data; a processing unitoperatively coupled to said analogue to digital converter, saidprocessing unit configured to receive and process said stream of digitaldata into a processed signal representative of said physiologicalsounds; and a display device operatively coupled to said processingunit, said display device configured to display a plurality of icons,wherein each icon of said plurality of icons displayed respectivelycorrespond to at least one operation of a plurality of operations thatsaid processing unit is configured to perform, wherein a sequence ofsaid plurality of operations is configured for customization by a userthrough insertion of an additional icon in said plurality of iconsdisplayed and modification of at least one operation of said pluralityof operations by said user through interaction with at least one icon ofsaid plurality of icons displayed, and wherein said processing unit isfurther configured to process said processed signal by said customizedsequence, and said display device further is configured to display acharacterization of said processed signal.
 2. The apparatus of claim 1,further comprising: a digital to analogue converter operatively coupledto said processing unit, said digital to analogue converter configuredto convert at least a portion of said processed signal into an analoguesignal for transmission over a wireless network.
 3. The apparatus ofclaim 2, further comprising: a serial to parallel converter operativelycoupled to said processing unit, said serial to parallel converterconfigured to convert at least a portion of said processed signal into aparallel output, and wherein said digital to analogue converter isconfigured to convert at least a portion of said parallel output into atransmission analogue signal for transmission over said wirelessnetwork.
 4. The apparatus of claim 3, wherein said processing unit isfurther configured to compute a mathematical transform or said portionof said parallel output prior to conversion into said transmissionanalogue signal.
 5. The apparatus of claim 3, wherein said processingunit is further configured to execute a fast Fourier transform on saidportion of said parallel output prior to conversion into saidtransmission analogue signal.
 6. The apparatus of claim 3, wherein saidphysiological sounds are sounds generated by an organ in a frequencyrange up to 20,000 Hz inclusive, and wherein said apparatus furthercomprises: a parallel to serial converter operatively coupled to saidprocessing unit, said parallel to serial converter configured to convertat least a portion of said parallel output into a serial output; and aport operatively coupled to said parallel to serial converter, said portconfigured to pass both at least a portion of said serial output and anelectrical energy, and wherein at least one icon of said plurality oficons facilitates a recording of said physiological sounds.
 7. Theapparatus of claim 1, wherein said display device is further configuredto display information relating to both a measured frequency and ameasured energy of said physiological sounds.
 8. The apparatus of claim1, wherein said analogue to digital converter is characterized as afirst analogue to digital converter, and said stream of digital data ischaracterized as a first stream of digital data, further comprising: anelectronic memory operatively coupled to said processing unit, saidelectronic memory configured for storage of information comprising anelectronic medical record; and a second analogue to digital converteroperatively coupled to said processing unit, said second analogue todigital converter configured to convert an analogue signal transmittedover a network in a direction toward said apparatus into a second streamof digital data, and said processing unit further configured to processat least a portion of said second stream of digital data.
 9. Theapparatus of claim 1, wherein a sample rate of said analogue to digitalconverter is configured to be altered by interaction of said user withat least one icon in said plurality of icons displayed.
 10. Theapparatus of claim 1, wherein said sensor is one sensor of a pluralityof sensors, wherein each sensor of said plurality of sensors comprises acorresponding diaphragm, and at least two sensors of said plurality ofsensors are configured to convert said physiological sounds, in responseto vibration of said corresponding diaphragm by said physiologicalsounds, into a corresponding plurality of electrical outputs; and saidanalogue to digital converter is one analogue to digital convertor of aplurality of analogue to digital converters, each analogue to digitalconverter of said plurality of analogue to digital converters isoperatively coupled to a corresponding one sensor of said plurality ofsensors, wherein said analogue to digital converters are configured toconvert at least a portion of said plurality of electrical outputs intoa plurality of streams of digital data, wherein said stream of digitaldata is one of said plurality of streams of digital data, and whereinsaid processing unit is further configured to process at least a portionof said plurality of streams of digital data.
 11. The apparatus of claim1, further comprising: a band-pass filter operatively coupled to saidsensor, said band-pass filter configured to generate a bandpass signalfrom a signal representative of said physiological sounds, and saidhand-pass filter is configured for modification of a passband byinteraction of said user with at least one icon of said plurality oficons displayed.
 12. The apparatus of claim 1, wherein said processingunit is further configured to execute an analysis program to processdata representative of imaging tests.
 13. The apparatus of claim 1,wherein said display device is further configured to display qualitativeinformation concerning a relative level of amplification of saidprocessed signal representative of said physiological sounds.
 14. Theapparatus of claim 1, wherein said processing unit is further configuredto provide a serial to parallel converter.
 15. An apparatus foracquiring and processing physiological sounds comprising: a plurality ofsensors each respectively comprising a corresponding diaphragm, whereinat least one sensor is configured to be positioned on a body surface,and at least two sensors of said plurality of sensors are configured toconvert said physiological sounds, in response to vibration of saidcorresponding diaphragms by said physiological sounds, into acorresponding plurality of electrical signals; a corresponding pluralityof analogue to digital converters each operatively coupled to acorresponding one sensor of said plurality of sensors, said analogue todigital converters configured to convert at least a portion of saidplurality of electrical signals into a plurality of streams of digitaldata; and a processing unit operatively coupled to the plurality ofanalogue to digital converters, said processing unit configured toprocess said plurality of streams of digital data, wherein at least aportion of said plurality of streams of digital data are input into aparallel to serial converter to generate a serial output.
 16. Theapparatus of claim 15, wherein said processing unit is furtherconfigured to compute a mathematical transform on at least said portionof said plurality of streams of digital data prior to conversion intosaid serial output.
 17. The apparatus of claim 16, wherein saidprocessing unit is further configured to compute said mathematicaltransform through execution of a fast Fourier transformation.
 18. Theapparatus of claim 15, further comprising: a digital to analogueconverter operatively coupled to said parallel to serial converter, saiddigital to analogue converter configured to convert at least a portionof said serial output into an analogue signal for transmission over awireless network.
 19. The apparatus of claim 15, wherein saidphysiological sounds are sounds generated by an organ in a frequencyrange up to 20,000 Hz inclusive, further comprising: an input analogueto digital converter operatively coupled to said processing unit, saidinput analogue to digital converter configured to convert an analoguesignal transmitted over a network in a direction toward said apparatusinto an input stream of digital data, and said processing unit furtherconfigured to process at least a portion of said input stream of digitaldata.
 20. The apparatus of claim 19, wherein said analogue signal isrepresentative of a set of instructions, wherein said processing unit isfurther configured to execute said set of instructions.
 21. Theapparatus of claim 20, wherein said set of instructions comprises adevice driver configured to facilitate interaction by said processingunit with at least one analogue to digital converter of said pluralityof analogue to digital converters.
 22. The apparatus of claim 15,further comprising: an electronic memory operatively coupled to saidprocessing unit, said electronic memory configured for storage ofinformation comprising an electronic medical record.
 23. The apparatusof claim 15, wherein said plurality of sensors comprises at least threesensors.
 24. The apparatus of claim 15, wherein said physiologicalsounds are sounds generated by an organ in a frequency range up to20,000 Hz inclusive, said corresponding plurality of analogue to digitalconverters are characterized as a first analogue to digital converter,and said plurality of streams of digital data are characterized its afirst stream of digital data, and said apparatus further comprising: asecond analogue to digital converter, which is different than said firstanalogue to digital converter, operatively coup led to said processingunit, said second analogue to digital converter configured to convert,transmission analogue signal transmitted over a wireless network in adirection toward said apparatus into a second stream of digital data,and said processing unit further configured to process at least aportion of said second stream of data; a filter operatively coupled tosaid second analogue to digital converter, said filter configured forfiltering said second stream of digital data into a filtered stream ofdigital data, and wherein said processing unit is further configured totransform at least a portion of said filtered stream of digital datainto a frequency domain representation; and an electronic memoryoperatively coupled to said analogue to digital converter, saidelectronic memory configured to store a signal representative of saidsecond stream of digital data, and wherein said transmission analoguesignal is transmitted over said wireless network as a plurality offrequencies which are orthogonal to each other.
 25. The apparatus ofclaim 15, said apparatus further comprises: a display device operativelycoupled to said processing unit, said display device configured tooutput an icon to a user for facilitation of selective connection anddisconnection of said apparatus, by said user, to a wireless network.26. The apparatus of claim 15, further comprising: a band-pass filteroperatively coupled to at least one sensor of said plurality of sensors,said band-pass filter configured to generate a bandpass signal from asignal representative of one electrical signal of said correspondingplurality of electrical signals prior to transmission over a wirelessnetwork, wherein a passband of said band-pass filter is configured to bemodifiable by a user.
 27. The apparatus of claim 15, wherein saidprocessing unit is further configured to measure a quantity of datatransmitted over a network by computing a block size.
 28. The apparatusof claim 15, further comprising: a display device operatively coupled tosaid processing unit, said display device configured to display aninformation relating to both a measured frequency and a measured energyof said physiological sounds.
 29. An apparatus for acquiring andprocessing physiological sounds comprising: a sensor comprising adiaphragm, wherein said sensor is configured to be positioned on a bodysurface, and said sensor is configured to convert analogue signals, inresponse to vibration of said diaphragm by said physiological sounds,into an electrical output representative of said physiological sounds; aprocessing unit operatively coupled to said sensor, said processing unitconfigured to receive and process a stream of digital datarepresentative of said electrical output into a processed signalrepresentative of said physiological sounds; and a display deviceoperatively coupled to said processing unit, said display deviceconfigured to display a plurality of icons, wherein each icon of saidplurality of icons displayed respectively correspond to at least oneoperation of a plurality of operations that said processing unit isconfigured to perform, wherein a sequence of said plurality ofoperations is configured thr customization by a user through insertionof an additional icon in said plurality of icons displayed andmodification of at least one operation of said plurality of operationsby said user through interaction with at least one icon of saidplurality of icons displayed, and wherein said processing unit isfurther configured to process said processed signal by said customizedsequence, and said display device further is configured to display acharacterization of said processed signal.
 30. The apparatus of claim29, wherein said characterization comprises information relating to alevel of amplification of said processed signal.
 31. The apparatus ofclaim 29, wherein said characterization comprises information relatingto a cut off frequency in filtering said processed signal.
 32. Theapparatus of claim 29, wherein said apparatus is characterized as afirst apparatus, said processing unit is characterized as a firstprocessing unit, and said processed signal is characterized as a firstprocessed signal, further comprising: a second apparatus operativelycoupled to said first apparatus, said second apparatus comprising: anelectronic memory configured to store a signal representative of atleast a portion of said first processed signal representative of saidphysiological sounds as a stored signal; and a second processing unitoperatively coupled to said electronic memory, said second processingunit configured to retrieve said stored signal from said electronicmemory and process said stored signal into a second processed signal.33. The apparatus of claim 29, wherein said physiological sounds aresounds generated by an organ in a frequency range up to 20,000 Hzinclusive.
 34. The apparatus of claim 29, wherein said physiologicalsounds are cardiovascular sounds, and said display device is configuredto display a signal amplitude and a unit of time.
 35. The apparatus ofclaim 29, wherein said physiological sounds are sounds generated by anorgan in a frequency range up to 20,000 inclusive, said stream ofdigital data is characterized as a first stream of digital data, andsaid processed signal is characterized as a first processed signal,further comprising: a digital to analogue converter operatively coupledto said processing unit, said digital to analogue converter configuredto convert at least a portion of said first processed signal into atransmission analogue signal for transmission over a wireless network,wherein said transmission analogue signal is transmitted over saidwireless network as a plurality of frequencies which are orthogonal; andan analogue to digital converter operatively coupled to said processingunit, said analogue to digital converter configured to convert an inputanalogue signal transmitted over said wireless network in a directiontoward said apparatus into a second stream of digital data, and saidprocessing unit further configured to process at least a portion of saidsecond stream of digital data into a second processed signal.
 36. Theapparatus of claim 29, wherein said characterization comprisesinformation relating to a duration of a recording of said processedsignal.
 37. The apparatus of claim 29, wherein said analogue signals arecharacterized as a first analogue signal, and said processed signal ischaracterized as a first processed signal, further comprising: awireless network device operatively coupled to said processing unit,said wireless network device configured to transmit a second analoguesignal over a network towards said processing unit, wherein saidprocessing unit is further configured to process a signal representativeof said second analogue signal into a second processed signal.
 38. Theapparatus of claim 37, wherein said characterization comprisesqualitative information relating to a strength of said first processedsignal or said second processed signal.
 39. An apparatus for acquiringand processing physiological sounds comprising: a plurality of sensorseach respectively comprising a corresponding diaphragm, wherein at leastone sensor is configured to be positioned on a body surface, and atleast two sensors of said plurality of sensors are configured to convertsaid physiological sounds, in response to vibration of saidcorresponding diaphragms by said physiological sounds, into acorresponding plurality of electrical signals; and processing unitoperatively coupled to said plurality of sensors said processing unitconfigured to process a plurality of streams of digital datarepresentative of said corresponding plurality of electrical signals,wherein at least a portion of said plurality of streams of digital dataare input into a parallel to serial converter to generate a serialoutput.
 40. The apparatus of claim 39, further comprising: a portoperatively coupled to at least one of said plurality of sensors, saidport configured for passing a signal representative of saidphysiological sounds; and a speaker operatively coupled to said port,said speaker configured to convert said signal representative of saidphysiological sounds into an acoustic energy heard by a user.
 41. Theapparatus of claim 39, further comprising; a first filter operativelycoupled to one sensor of said plurality of sensors, said first filterconfigured to filter one electrical signal of said correspondingplurality of electrical signals generated by said one sensor before saidelectrical signal is converted into one digital stream of said pluralityof streams of digital data; and a second filter operatively coupled tosaid parallel to serial converter, said second filter configured tofilter at least a portion of said serial output.
 42. The apparatus ofclaim 39, further comprising: a display device operatively coupled tosaid processing unit, said display device configured to display aplurality of icons, wherein each icon of said plurality of iconsdisplayed respectively correspond to at least one operation of aplurality of operations that said apparatus is configured to perform.43. The apparatus of claim 39, further comprising: a display deviceoperatively coupled to said processing unit, said display deviceconfigured to display a plurality of icons, wherein said plurality oficons displayed on said display device is configured for customizationby a user through insertion of an additional icon in said plurality oficons displayed, and wherein a recording of said physiological sounds isinitiated by interaction of said user with at least one icon in saidplurality of icons displayed.
 44. The apparatus of claim 39, whereinsaid processing unit is further configured to selectively decrease apower level within a signal representative of at least a portion of saidcorresponding plurality of electrical signals when said power level isabove a pre-determined threshold.
 45. The apparatus of claim 39, whereinsaid processing unit is further configured to selectively decrease apower level within a signal representative of at least a portion of saidcorresponding plurality of electrical signals when said power level isbelow a pre-determined threshold.
 46. The apparatus of claim 39, whereinsaid apparatus is characterized as a first apparatus, and saidprocessing unit is characterized as a first processing unit, and furthercomprising a second apparatus operatively coupled to said firstapparatus, said second apparatus comprising: an electronic memoryconfigured to store a signal representative of at least a portion ofsaid serial output; and a second processing unit operatively coupled tosaid electronic memory, said second processing unit configured toretrieve from said electronic memory and process said signalrepresentative of at least said portion of said serial output into aprocessed signal.
 47. The apparatus of claim 39, wherein said processingunit further comprises: a program memory for storing a set ofinstructions, wherein said processing unit is further configured toexecute said set of instructions; and a data memory configured forstorage of at least a portion said plurality of streams of digital data,and wherein said program memory and said data memory are coupled toseparate buses.
 48. The apparatus of claim 39, wherein a first sensor ofsaid at least two sensors is configured to convert said physiologicsounds from a first organ, a id a second, different sensor of said atleast two sensors is configured to convert said physiologic sounds froma second, different organ.
 49. The apparatus of claim 39, wherein afirst sensor of said at least two sensors is configured to convert saidphysiologic sounds in a first frequency range, and a second, differentsensor of said at least two sensors is configured to convert saidphysiologic sounds in a second frequency range, wherein said firstfrequency range and said second frequency overlap in frequency ranges,and said first frequency range and said second frequency range aredifferent.
 50. The apparatus of claim 39, further comprising: anelectronic memory operatively coupled to a first sensor of said at leasttwo sensors, wherein said first sensor is configured to convert saidphysiologic sounds at a first time, and said electronic memory isconfigured to store a signal representative of at least a portion ofsaid physiologic sounds converted by said first sensor as a firstoutput, and a second, different sensor of said at least two sensors isconfigured to convert said physiologic sounds at a second, differenttime into a second output.
 51. The apparatus of claim 50, wherein saidfirst output and said second output are representative of at least aportion of said plurality of streams of digital data.
 52. The apparatusof claim 39, wherein a first sensor of said at least two sensors isconfigured to convert said physiologic sounds of a first amplitude froman organ, and a second, different sensor of said at least two sensors isconfigured to convert said physiologic sounds of a second, differentamplitude from said organ.